Solar water heating systems
Posted by Solar energy guru | Filed under Solar thermal solutions
Did you know that simply heating your water can account for 14% of your annual home energy costs? That’s one of the major reasons so many people are now turning to solar water heating for their hot water needs. The other reason that solar water heating is becoming more popular is that it helps reduce the environmental impact compared to other home energy sources.
Solar water heating captures the sun’s energy with some sort of collector setup and then this heat is used to warm either air or a fluid. This air or fluid then is transferred to the home’s water tank producing hot water. The solar water heating system can be a direct or indirect system, depending on the typical climate of the region where the home is located. Typically, an indirect system is needed in less sunny climates or areas that get temperatures below freezing. A direct system is used where there is a warmer, sunnier climate.
The most common solar water heating system uses a flat panel collector with an absorber plate to capture the heat energy from the sun. The collector has flow tubes through the collector which are often filled with a propylene glycol/water mixture. Since this mixture doesn’t freeze, it’s a good system for northern climates or anywhere the gets sub-freezing temperature drops.
These flow tubes allow the heated fluid inside to travel to heat exchangers in a water storage tank. These exchangers help to transfer the heat from the flow tubes to the stored water. By using the antifreeze fluid in the flow tubes, it also protects the pipes throughout the system from freezing and breaking.
When in a warm, sunny climate, solar water heating is more often done directly. This type of system allows the drinking water to circulate directly through the solar collector to heat and go to the storage tank. The circulating pump which keeps the water flowing through the system can use differential or photovoltaic controllers to control the operation.
Passive solar water heating systems are also used in sunnier climates. This is the most simple and reliable solar water heating system of all as it uses no pumps or other parts that need electricity. Like most passive solar energy techniques, it is much more cost effective if the system is incorporated into the building plans for a new home design.
Most of the time, solar water heating will not take care of all of your home’s hot water needs. Depending on the climate where you live, you can usually expect to cover anywhere from 50% up to 80% of the home’s hot water needs. Even in the sunniest climes, there are occasionally cloudy or rainy days. To be certain of always having the hot water you require, a back up electric or gas water heater is usually recommended.
For those who are interested in pursuing solar energy for their homes but can’t afford $20,000 or more for a full home solar power system, solar water heating is an easy and affordable way to begin using solar power in your home. The cost of solar water heating systems installed begins around $2000 and goes up to around $5000. The costs, of course, will depend on what type and size of solar water heating system that you need.
Solar water heating is an excellent way to help reduce your family’s dependence on fossil fuels as well as reduce your monthly utility bills. Not only will you save money on your household energy costs, you are also helping the environment. Solar water heating is one solar technology that has a relatively short payback time since it’s fairly low cost and a solar hot water system will last up to thirty years.